Fuel pump



sept. 23,1941;

2 Sheets-Sheet lv is also utilized.

Patented Sept. 23, 1941 FUEL PUMP Arthur C. Kleckner,

mesne assignments,

3 Claims.

The present invention relates to fuel pumps, and is particularly concerned with fuel pumps of the two stage gear type. By a two stage pump I Racine, Wis., assignor, by

to Webster Electric Company, Racine, Wis., a corporation of Delaware Application December 8, 1938, Serial No. 244,591

(Cl. 10S-126;

mean a pump having its parts so arranged that two parts of the pump are adapted to perform different functions, such as, for example, the suction of a large supply of liquid fuel to the pump and the discharge of liquid fuel from the pump at a suitable pressure and in suitable volume for an oil burner.

The present fuel pump is an improvement over that disclosed in my prior Patent No. 2,009,137, issued July 23, 1935, on Multi-stage pump and pumping systems, in which one set of small gears is used for the high pressure stage of the pump and another set of larger gears, that is, longer gears are used for the suction stage.

One of the objects of the present invention is the provision of an improved multi-stage pump in which the number of operating parts and stationary parts is reduced so that the pump may be constructed more economically and may be placed within the means of a larger number of purchasers.

Another object of the invention is the provision of a simpler type of multi-stage pump in which a lesser number of gears is employed and therefore a lesser number of gear housing plates Anotherobject of the sion of an improved multi-stage pump in which the various gears are so arranged that parts of the gears are employed for one purpose and other parts for another purpose, so as to bring about the accomplishment of the two separate funcinvention is the provi- 'Cil tions of multi-stage pumps of this type by a lesser number of gears.

Another object of the invention is the provision of an improved multi-stage pump which is sturdy, economical, eilicient, self-priming, and adapted to perform its functionsof providing a supply 0f liquid fuel under substantially constant pressure and at substantially constantyvolume at the nozzle of an oil burner under all kinds of adverse conditions. Y

Other objects and advantages of the invention wlil be apparent from the following description and the accompanying drawings, in which similar characters of reference indicate similar parts throughout the several views.

Referring tothe two sheets of drawings accompanying this specification,

Fig. 1 is a side elevational view, with the reservoir housing in partial section, showing the interior of the fuel pump and the exterior of the attached units, such as the strainer housing and regulator valve housing;

Fig. 2 is a sectional view, taken on the plane of the line 2--2 of Fig. 1, looking in the direction of the arrows;

Figs. 3, 4, and 5 are fragmentary sectional views similar to Fig. 1 and relate to a pump of similar structure, with similar gear arrangements, but having a different arrangement of in-l let and discharge conduits, whereby it ls shown that the pump may be so arranged that it may be operated for left hand or right hand rotation, with the intake on the left or the intake on the right.- For example, in Fig. l the central or driving gear is arranged for clockwise rotation and the liquid intake is on the right hand. In Fig. 3 the main or central shaft is arranged for rotation in a counterclockwise direction,` liquid intake or strainer would be on the left. In Fig. 4 the main shaft is arranged for counter- -clockwise rotation and the liquid fuel intake or strainer is on the right. In Fig. 5 the shaft is arranged for clockwise rotation, with the liquid intake or strainer on the left.

The foregoing conditions are conditions which might have to be met by the manufacturer of the pump, to supply the needs of various manufacturers of oil burners, as some manufacturers have the fuel unit so located and arranged that it must rotate in one direction and others in the opposite direction, and some prefer the strainer on the left, and others on the right.

Referring to Fig. 1, I0 indicates the fuel unit, which preferably comprises a metal casting, having a fuel regulator valve I I, a pump reservoir I2, and a strainer housing I3.

The present pump structure embodied in separate pumps,

may, however, be from which the vregulator valve II, strainer I3, and pump reservoir may have been completely eliminated, and the structure described is merely one of the preferred embodiments of the invention.

The pump unit casting is provided with a main body I4, which is formed with a by-pass chamber I5 located between the regulator valve chamber II and strainer chamber I3, and adapted to be utilized for receiving the excess of fuel over that utilized by the nozzle of the oil burner.

The unit preferably has a tubular projection I6 at the right adapted to house a shaft seal, preferably of the type utilizing a bellows diaphragm, whereby the main shaft II may be rotatably mounted, and maintains a fluid-tight condition, with a minimum amount of friction and leakage.

The main body of the unit I4 is provided with but the a transversecyli'ndrical bore I8 for receiving a bearing bushing I 9, serving as the main bearing of the shaft I 1. .'I'he shaft projects from the unitv at the right, as shown in Figi 2.

'I'he body Il is provided With a substantially l5 plane surface 28,.which is adapted to engage a similar siu'face 2| on a pump bearing plate 22. 'I'he body I4 may be provided with a pair yof transverse cylindrical bores 23, 24, the axes of which are parallel, and which are adapted to rel0- for placing the reservoir chamber 28 in communi- '15 cation with the by-pass chamber I5. 'I'he reservoir chamber 28 is provided by means of a cover plate 85, which embraces all of the vpump plates and has its `edge 88 engaging a gasket 81, which engages the plane surface 28 20' of the pump body I4.l The cover is secured-in place by a plurality of screw bolts 58, which pass through apertures in the cover and are threaded into'the bodyl I4.

The pump preferably comprises a plurality of 25 the plates, such as the bearing plate 22, the gear housing plate 29, and the cover plate 38. Each of the plates isprovided with a bore 3| for receiving the tubular-' v member 28 and a bore 32 for receiving the alignment pin 25. Thus the plates 3o may be more accurately aligned by means of theA members 25, 28 than could be accomplished by the threadedl screws 33, which pass through apertures in the three plates 22, 29,' and 38, and are threaded into the body I4. clamp the plates of the pump together, and, as theA plates are all ground to substantially plane engaging surfaces, a substantially liquid-tight construction is secured.

The bearing plate 22 is formed with a plurality 40 of cylindrical bearing bores 34, 35, and- 38'for receiving ythe shafts 31, I1, and 38, respectively.. If desired, shafts 31 and 38 may be wholly eliminated, and the bearing plate 22 also wholly eliminated, since the gears may mounted in suitable sockets in the gear housing plate 29, so as to eliminate the necessity for separate shafts for each gear except the main driving shaft I1. v

'I'he gear housing4 plate, like the bearing plate 50 22 and the cover plate 38, may comprise a ground steel plate, and the gear housing plate is formed with a plurality of intercommunicating gear sockets or cylindrical bores 39, 48, 4I. Each of the bores 39, 484I houses one of the gears 42, 55

43, 44, which are preferably vgears provided with helical teeth, in order that the gears may not only carry the liquid in the tooth grooves, but may tendto force the liquid toward discharge at a predetermined edge of the gear. 60

The gears 42-44 are all drivenby the shaft t I1, due to the inter-engagement between the teeth of the gear 42 with the gear 43, and those of the teeth 44 with the gear 43. l The partially cylindrical bores or sockets 3965 48, 4I are so arranged vthat they engage the-.fv periphery of the gear teeth of gears 42-44 when the gears are inter-meshed with each other. As a matter of practice, the gear centers 45, 4 8.; 41 are preferably arranged inan align-v 70 ment, but are not necessarily so arranged in the present case. v

In the embodiment of Fig. 1 the arrow at thev gear 43 indicates that the shaft I1 may rotate 4vin a'clockwise direction. Inthis case the body'75 The screw bolts 33 35 be rotatably 45 I4 and bearing plate 22 are provided with an intake port 48 located to communicate with the two gear sockets 39 and 48 at 'the point of their juncture on the right hand of Fig. l; that is, theintake port is located where the teeth of thev gears 42 and 43 begin to separate, and port 48 may be connected by Aconduit '49 with any fuel tank or any complete unit having the strainer. It leads through conduit 50 to theV upper part of the strainer chamber I3.

Liquid fuel is in every case taken in the lower port or side of the strainer chamber at 5l or i2 and passes through the strainers and out of thes upper part of the strainer chamber to the pump inlet at 48. In most cases the lateral port 52 is utilized for a partial gauge.

The body I'4 or the bearing plate 22 may be provided with a liquid discharge port 53 at the opposite side of the gears 42, 43, the port 53 being connected by a conduit 54, chamber 28, and conduit 55, with a. liquid intake port 58y disposed at the left hand side ofr the engaging teeth of gears 43 and 44.-

The pressure discharge port 51 may be formed in body I4 or bearing plate 22 at the right hand of the inter-engaging teeth of' gears 43 and 44, and it may be connected by a transverse conduit 58 located either in the body I4 or bearing plate 22, with an upwardly extending conduit 59 which leads to a discharge port 88 leading into the regulator valve chamber II.

In the event of the incorporation of the pump in a unit having such a regulator valve, the regulator valve is adapted to discharge fuel at substantially constant pressure and in'substantially constant volume at the nozzle port 8|, and the balance of the fuel from the regulator valve is by-passed into the by-pass chamber I5 in the same manner as disclosed in my prior Patent No..2,051,301 on Fuel supply units for oil burners, or the like, issued August 18, 1936.

The operation of the'g'ear pump in two stages is as follows: Liquid fuel is sucked up through the intake conduits 49, 58 and intake port 48- where it is discharged through the conduit 54 into reservoir 28. A similar amount'is taken up into the gear tooth space of gear 43 at the right from intake port 48 and carried downto the pressure discharge conduit 51. L'I'he outletport of the pump. such as the by-pass port 21 from the reservoir, is arranged above the gears 42-44 so that the tooth spaces are always lled with liquid fuel after the pump has once been run, and this facilitates an immediate supply of liquid fuel under pressure when the pump starts.

Even in the absence of liquid fuel between the gear spaces, the tooth spaces of gear 42 carry liquid fuel which is discharged against nothing but atmospheric pressure and, as that portion ofthe pump does not work against any pressure except the resistance of the conduits, it

is adapted to draw up liquid fuel and provide an v immediate supply of liquid fuel for :filling a' 55. The gear teeth of gear 44, however, take liquid fuel from the conduit 55 and reservoir 28 at the intake port 56 and carry it around in a counter-clockwise direction, as indicated by the arrows, and discharge it at the pressure discharge port al.

The gears 42, 43, 44 are all of the same length. and same size gear teeth and tooth spaces, but due to the fact that the gear teeth of gear d2 are not working against any pressure, except the resistance of the conduits, they pump a larger amount and an excess of liquid fuel over that pumped by the teeth of gear 44 and the teeth of gear 43 at the right hand side, which are working against a very high pressure. The result is that there is a greater slippage or leakage in the lower part of the pump, comprising the teeth of gear .44, than there is at the upperpart of the pump at the teeth of gear 42, and the net result is that there is a larger amount of liquid fuel drawn up to the pump for use by the high pressure gear than is discharged at the discharge port 51 of the high pressure stage.

Thus -a two stage arrangement is provided by using only three gears instead of four, and the gears are all of the same size, thus reducing the number of different parts. A number of pump plates have been eliminated, such as the plates which would be required for a the larger and smaller gears in my prior patent and the plate which would be required for housing the extra pair of gears utilized in such devices of the prior art. Thus the present invention may be constructed at a much lower cost than the devices of the prior art.

Referring to Fig. 3, this is a pump of similar construction, but the conduits have been reversed with respect to those of Fig. 1 because of having the -main shaft operate in the opposite direction. The intake in this case is at the left hand side of the pump, as indicated by the conduit 50.

In this case the low pressure stage is at the lower gear 44 and the high pressure stage is at the upper gear 42, liquid fuel at high pressure being discharged at the port 51.

Referring to Fig. 4, in this embodiment the voir 28, and conduit I low pressure stage is again at the lower gear 44,

the intake being at the conduit 50, and the high pressure stage is at the uppermost gearA 42, the outlet 51 being at the right hand side of the gears. In this case the main shaft operates counter-clockwise, and the strainer is on the right hand.

Referring to Fig. 5, in this case the main shaft operates in a clockwise4 direction, with the strainer arranged on the left hand and the intake of the pump being at the conduit 50, again on the left end. The high pressure outlet of the pump is at the left side at the port 51 adjacent the lowermost gear 44, and connected by suitable conduits to the high pressure outlet port 60.

It will thus be observed that I have invented an improved gear pump of the multi-stage type which requires a lesser number of gears than any of the devices of the prior art. The gears for the low pressure stage and the high pressure stage may be of the same size, but I utilizeV the characteristic of greater slippage in the high pressure gear in such manner that an excess of liquid fuel is pumped by the low pressure gear to assure a constant supply of liquid fuel to the high pressure gear.

Due to the elimination of the extra gear and elimination of gear housing plates, the present partition between.

pump may be constructed at a lower cost and may be placed within the means of a larger number of purchasers, and the ultimate cost of an oil burner to the consumer is thereby reduced.

While I' have illustrated a preferred embodiment of my invention, many modifications may be made without departing from the spirit of the invention, and I do not wish to be limited to the precise details of construction set forth, but desire to avail myself of all changes within the scope of the appended claims.

Having thus described my invention, what I- claim as new and desire to secure by Letters Patent of the United States, is:

1. In a liquid pump of the gear type, the combination of a gear housing comprising a housing plate having interconununicating cylindrical apertures for three gears, gears arranged in said apertures, means for engaging the ends of said gears to effect a closure of said housing, said gears being arranged to be driven from one 0f lthe gears, and said one of said gears beingr provided with a drive shaft, said housing being provided with a low pressure inlet and a low pressure outlet `at the intersection of two of said gears, predetermined parts of which two gears constitute a low pressure stage, a. reservoir, said low pressure outlet being in communication with said reservoir at substantially atmospheric pressure, and said housing having an inlet at another intersection of predetermined ones of said gears communicating with said reservoir, and having plate having intercommunicating cylindricalapertures for three gears, gears arranged in said apertures, means for engaging the ends of said gears to elect a closure of said housing, s'aid gears being arranged to be driven from one of the gears, and said one of said gears being provided with a drive shaft, said housing being provided with a low -pressure inlet and a low pressure outlet at the intersection of two of said gears, predetermined parts of which two gears constitute a low pressure stage, a reservoir, said low pressure outlet being in communication with said reservoir at substantially atmospheric pressure, and said housing having an inlet at another intersection of predetermined ones of said gears communicating with said reservoir,l and having a high pressure outlet at the opposite side of the intersection of said latter gears, certain parts of said predetermined ones of said gears constituting the high pressure stage, the low pressure stage of said gears pumping an excess of volume of liquid over the high pressure stage of said gears, due to the difference in resistance to the discharge of fuel from the gears of said stages, said reservoir comprising an enclosure surrounding the body of said pump, and maintaining said housing plate immersed in liquid, said reservoir having a by-pass outlet located above the inlet to said high pressure stage whereby the liquid in said reservoir is adapted to prime said high pressure stage.

nicating cylindrical apertures for receiving three gears arranged in a series, one of said'gears being 'connected to said drive shaft, la reservoir, said housing having an inlet conduit communicating with' two of said gears adjacent their points loi? Y engagement on theV side toward which said latter two gears are rotating, said housing also having 10 aV discharge aperture leading from the opposite side'of said latter two gears tosaid reservoir, whereby liquid'fuel is discharged into the reservon, and said reservoir having a return mais in communication ,with the inlet conduit of said pump, said housing also having a high pressure intake communicating Jwith said reservoir and' leading to the point of intersection of the third gear and one of the gears of said iirst-men- A tioned two gears, and said housing having a high pressure outlet leading from the intersection of said latter two gears, whereby an' excess of fuel is pumped up to said reservoir and a predetermined volume is discharged from said pump at high pressure.

ARTHUR C. KLECKNER. 

